People have continually attempted to impart certain functional properties to a surface by applying coatings to it. Many medical devices, such as urinary and cardiovascular catheters, syringes, and membranes need to have a lubricant applied to the outer and/or inner surface to facilitate insertion into and removal from the body and/or to facilitate drainage of fluids from the body. Lubricious properties are also required so as to minimize soft tissue damage upon insertion or removal. Especially, for lubrication purposes, such medical devices may have a hydrophilic surface coating or layer which becomes lubricious and attains low-friction properties upon wetting, i.e. applying a wetting fluid for a certain time period prior to insertion of the device into the body of a patient. A hydrophilic surface coating or layer which becomes lubricious after wetting is hereinafter referred to as a hydrophilic coating. A coating obtained after wetting is hereinafter referred to as a lubricious coating.
Coating formulations for use in such lubricious coatings may comprise for example a multifunctional polymerizable compound, which is polymerized upon curing in the presence of an initiator and which provides improved robustness of the coating as well as a controllable network which will allow tuned release of for example metal ions and/or other anti-microbial agents, and also allow entrapment of for example extractables. Moreover a hydrophilic polymer may be present to provide a higher hydrophilicity of the coating, and/or to provide an improved dry-out time. Preferably all the components of said coating formulations are sufficiently hydrophilic in order to obtain a homogeneous mixture of said components resulting in favorable coating performance.
In WO 2006/056482 A1 a hydrophilic coating is disclosed comprising a supporting polymer (polyethylene glycol diacrylate, PEG4000 diacrylate, number average molecular weight of the polyethylene glycol 4000 g/mol), a hydrophilic polymer (polyvinylpyrollidone, PVP) and an initiator.